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    <script>
        // const obj = {};
        // let a = Symbol('a');
        // let b = Symbol('b');
    
        // obj[a] = 'Hello';
        // obj[b] = 'World';
    
        // const objectSymbols = Object.getOwnPropertySymbols(obj);
    
        // console.log(objectSymbols);

        // let s1 = Symbol.for('foo');
        // let s2 = Symbol.for('foo');
        // console.log(s1 === s2);
        // console.log(Symbol('foo') === Symbol('foo'));

        // let s1 = Symbol.for("foo");
        // console.log(Symbol.keyFor(s1));
        // let s2 = Symbol("foo");
        // console.log(Symbol.keyFor(s2));
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